The present invention relates generally to operation information recording/reproducing apparatus and methods suited for use in digital mixing consoles etc., as well as time code generating apparatus and methods pertaining to the operation information recording/reproducing apparatus and methods.
Generally, the digital mixing consoles known today include a user-operable operation panel having an electromotive fader unit, a DSP (Digital Signal Processor) for processing audio signals, and a CPU for detecting operational states of the operation panel and establishing algorithms for the DSP on the basis of the detected operational states. Among the known digital mixing consoles is one having a so-called “automix” function. The automix function is intended to automatically set fader operation amounts, equalizing amounts, etc., in accordance with the passage of time, in synchronism with external equipment, such as a video tape recorder, digital tape recorder or MIDI sequencer.
Recording processing by the automix function is carried out as follows. First, a time code is supplied, along with information of video, audio and/or the like, from external equipment to the mixing console. As the user manipulates or operates the electromotive fader unit or the like, event data are sequentially recorded in a memory or the like. The event data to be recorded here include operation data indicative of the contents of the user's operation and “time stamps” corresponding to values of the time code at the time of the user operation.
These various event data will be generically called “automix data”. In reproduction, a time code is supplied again, along with information of video, audio and/or the like, from the external equipment to the mixing console, as in the recording. In the mixing console, the corresponding event data, included in the auto mix data, are read out in accordance with a progression of the supplied time code, and the electromotive fader unit etc. are automatically driven in accordance with the operation data included in the event data.
Conventionally, any desired type of the time code supplied from the external equipment is variably selectable from several types, such as “30”, “30drop”, “25” and “24”, classified according to the resolution per second. These values are predetermined in accordance with the frame frequencies in various image recording methods. The time code of resolution “30” is based on the frame frequency of “29.97” Hz in the NTSC system; namely, the frame frequency “29.97” Hz is rounded off to the integral value “30”. The time code of resolution “30drop” is intended to cause a broadcasting time to coincide with that of the frame frequency “29.97” Hz, by periodically inserting a value of the “second” of resolution “29” in resolution “30”. Further, the time code of resolution “25” represents the frame frequency of the PAL system, and the time code of resolution “24” represents the frame frequency of movie films.
However, in cases where event data are recorded with a time code of a given resolution, the conventional mixing console could not reproduce the recorded event data using a time code of a resolution different from the given resolution. Thus, if the recorded format of images is changed using, for example, a “telecine” converter, the automix data recorded before the change of the recorded format could not be used by the conventional mixing console.